Circular loom



March 6, 1934.I w. R, MAcl-:WAN Er AL 1,949,571

CIRCULAR LOOM Filed May 20, 1932 Patented Mar. 6, 1934 UNHTED STATES PATENT `OFFICE CIRCULAR LooM land Application May 20, 1932, Serial No. 612,602.

Great Britain June 20, 1931 Claims.

This invention relates to circular looms of the type in which the warp shed is formed substantially parallel with the central axis of weaving,

or, in other words, lies substantiallyin a cylinl drical surface co-axially of said weaving axis. A loom of this type is described and claimed in United States Patent #1,860,975 and in a loom according to this prior patent, the warp threads pass in a direction substantially parallel with, l0 or inclined at a comparatively small angle to, the central axis of weaving through a stationary reed-like annular frame, each radial cross memf ber of which latter is formed with an undercut transverse recess in which a shuttle carrier is adapted to engage so as to be restrained positively to travel in a path determined by said recessed cross members. In this loom the axis of weaving is vertical, and a plurality of levers, pivoted intermediately of their lengths about horizontal axes, extend each radially inwards from its pivotto engage in the groove ofa cylindrical grooved cam concentric with the weaving axis, and radially outwards from its pivot to pass, as it is rocked about said pivot by the action of said cam, through the warp shed to co-operate with a shuttle or its carrier to impel the shuttle, and to bear subsequently against the deposited weft thread to beat-up said thread.

In the loom in question there is provided a vertical drive shaft, the axis of which is coincident with the axis of weaving, and upon which the cylindrical grooved cam is fast; there being also fast upon the shaft below the cam, eccentrics or equivalent means for operating healds or heddle frames extending radially beneath the reed-like annular frame, and also a further eccentric or equivalent means for maintaining the tension or" the warp threads substantially constant as the warp shed is formed and reformed.

In the loom described and claimed in United States Patent #1,860,975, a rigid stationary ring over which the warp threads pass to the heddle mechanism from the usual rigid stationary warp thread distributing ring is located just above the latter ring Within the circular series of Warp threads, and for maintaining constant tension of the warp threads, a flexible hoop or ring of a diameter smaller than either of said xed rings surrounding the series of warp threads to draw them inwardly towards the central drive shaft as they pass between said fixed rings. This flexible hoop or ring is connected at intervals around its periphery by radially disposed tie rods toan endless chain forming a collar or strap around an ellipsoidal eccentric fast upon the drive shaft,

and, as all the tie rods are of equal lengths, the flexible hoop will assume a correspondingly ellipsoidal shape, the axis of which will rotate with the drive shaft, drawing the warp threads inwardly to a less extent Where the sheds are formed, and to a greater extent where the sheds are closed.

It has been found, however, that this arrangement, which inevitably comprises a considerable number of working parts, is ineflicient for the reason that it is impossible so perfectly to shape the eccentric that the control of the tensioning will be absolutely accurate, and for this reason the warp threads are subjected to an undesirable amount of strain. VIt is the object of the present invention to provide an improved warp thread tensioning means which, whilst ensuring perfect control of the tensioning of the warp threads, shall subject the latter to a minimum of strain.

I To this end and in accordance with the present invention, the improved warp thread tensioning means for use in a loom of the type referred to comprise simply a flexible hoop o-r ring of more or less springy material which encircles the central axis of weaving at that. side of the heddle mechanism remote from the shuttle path, said flexible hoop or ring being of such dimensions as to bear radially upon all the Warp threads and to be distorted out of its naturally circular form by the varying pressure of said threads thereon as the sheds are formed and reformed. This flexible tensioning hoop or ring, whilst free to move at all points radially inwards or outwards from the central axis of weaving, is restrained against axial motion and may be disposed Within the series of warp threads to bear outwardly thereagainst, or, if desired, may surround said series of threads to bear inwardly thereagainst.

The improved tensioning means are extremely simple, the only moving partbeing the ring itself to which movement is imparted by the warp threads themselves, so that perfect control of their tension results, and the only other parts are iixed parts, upon or within which the ring is free to move radially but not axially. It will be apparent to those skilled in the art that the ring will always assume an ellipsoidal form, and that this form will be exactly correct for maintaining even the tension of the warp threads for the reason that it is determined solely by the shed forming and reforming action itself.

One form of the invention is illustrated by the accompanying diagrammatic drawing of which,

Figure 1 is a fragmentary view showing in elevation the mounting of the ring below the warp shed,

Figure 2 is a diagrammatic plan view showing the configuration of the ring during use, and

Figure 3 shows in perspective the manner in which the warp threads pass through the tensionlng Ilng.

As shown, a plurality of outwardly extending arms 11 are carried by uprights 12 mounted upon the usual warp thread distributing ring 13. These arms 11 extend radially outwards over the ring 13 between it and the heddle mechanism (not shown) two adjacent heddles are indicated in Figure 1 at 14 and 15. Each arm 11 is formed with a slot 16 which is open at its outer end, and the iiexible ring or hoop itself, which is indicated at 17 is formed from more or less springy material of appropriate diameter and is supported in the slots 16 of the arms 11. In general, the ring or hoop will comprise a length of wire, one end of which carries a socket to receive the other end, this length of wire being passed around the series of warp threads indicated at 18 just below a xed ring 19 forming part of the warp distributing ring 13. It is found in practice that so long as one end of the wire comprising the ring or hoop 17 is a. fairly tight iit in the other socketed end the very small strain which is imparted to the warp threads 18 by this tensioning device will be quite insuiiicient to separate the ends from one another. It will be observed that the ring 17 may very easily be removed from or placed in position even by an unskilled person.

It will be observed also that during use the ring will be of more or less ellipsoidal formation as shown in Figure 2, the deformation of the ring from circular form being proportional to the change in length of the paths occupied by the warp threads 18 as the sheds are formed and reformed. In the case illustrated there are two sheds, shown at 20 and 21, with the junction therebetween at 22, in Figure 3 of the drawing. In Figure 1 of the drawing two warp threads 23 and 24 are shown in what may be termed their full shed position.

The improved warp thread tensioning means according to the invention not only enables the tension of said threads to be maintained constant throughout the operation of the loom with very great accuracy, but by its use the`warp threads are subjected to a negligible amount of strain only, and the improved means are so simple as to be Very inexpensive indeed and thoroughly reliable in operation.

What we claim iszl. Warp tensioning means for use in a loom of the type referred to comprising a exible ring of more or less springy material, and means specifically for supporting said ring and preventing appreciable motion thereof axially only, said ring encircling the central axis of weaving and being such as to bear radially upon the warp threads and to be distorted out of its natural circular form solely by the varying pressure of said warp threads thereon as the sheds are formed and reformed, against which pressure it is inextensible circumferentially.

2. A construction as described in claim 1, wherein the ring surrounds the series of warp threads and bears inwardly thereagainst.

3. A construction as described in claim 1, wherein the ring is in the form of a metal wire of appropriate length, 'one end of whichV is inserted removably into a socket secured at the other end thereof.

4. A construction as defined in claim l, wherein the ring is carried in open-ended slots formed in a plurality of supporting members extending radially of the central axis of weaving.

5. A construction as defined in claim 1, wherein the ring is carried in open-ended slots formed in a plurality of supporting members extending radially of the central axis of weaving through the series of warp threads and between two fixed rings of a diameter not less than the maximum transverse dimension of said ring.

WILLIAM ROBERTSON MACEWAN. JULIO IZAGUIRRE VILLA. 

